Discrete Cationic Complexes for Ring-Opening Polymerization Catalysis of Cyclic Esters and Epoxides

Redox Switchable Copolymerization of Cyclic Esters and Epoxides by a Zirconium Complex

“…Therefore, we evaluated the activity of the oxidant (Scheme 1) toward cyclic ethers. 12 Screening a number of oxidants led to disappointing results. NOBF4 has a higher oxidation potential than Ac FcBAr F , but its oxidation of the catalyst was not reversible ( In order to avoid a competition between CHO polymerization and the oxidation of (salfan)Zr(O t Bu)2, sequential monomer additions were employed for the formation of block copolymers that did not start with the oxidized catalyst ( Table 4).…”

Factors influencing catalytic behavior of titanium complexes bearing bisphenolate ligands toward ring-opening polymerization of L-lactide and ε-caprolactone

“…These polymers have vast applications in many fields [3,4]. Metal catalysts [5][6][7] have been commonly used as catalysts for the ROP of cyclic esters. Since PLA and PCL polymers have wide application in medical field, the minimization of residual hazardous metal in these polymers after synthesis is essential.…”

Copolymerization of Epoxides and CO2 by Cobalt(II) Oxaporphyrins with Mechanistic Explorations on Poly(Propylene Carbonate) Formation

“…The poly(propylene oxide) (PPO) formation by OTPPCoSbF 6 was considered to be a cationic polymerization in nature (activated chain end mechanism, ACE). In literature, a series of metal complexes, paired with weakly coordinating anions (including SbF 6 − ), has been reported to serve as cationic initiators for ring‐opening polymerizations . A probable mechanism of OTPPCoSbF 6 ‐catalyzed PPO formation is depicted in Figure .…”

“…In cationic ring opening of PO, there existed two possible side reactions, namely, chain transfer with water and cyclization . In the former case, the growing polymer chain may react with residual water to produce a polyether‐diol.…”